- Do not report start-up trap as stop reason should one trigger
while stepping.
- Set current frame to first usable frame, avoiding disassembly
while stepping
- Kill process in case of forced shutdown with pending (long)
commands.
- SymbolGroupValue: Do a quick check for accessible values
and mark failure as 'invalid'.
- Introduce flag indicating existence of simple dumpers to types.
Introduce node hierarchy and move nodes to a separate file.
Introduce reference nodes that point to additional symbols and
symbols within the symbol tree (make deeply nested linked list
elements visible as array elements). Properly name container
elements as array elements 0..n. Fix pre-expansion of complex
dumpers.
